Translations:Controls/5/en

Mouse modifiers locked to Sneak/Sprint || On: (Default) Shift + mouseclick actions are achieved by holding the Sneak key while clicking. Ctrl + mouseclick actions are achieved by holding the Sprint key. If Sneak is bound to the Shift key, and Sprint is bound to the Ctrl key, then this may be just fine. But if you re-bound Sneak or Sprint to something different - especially if you reversed them so that the Shift key is now Sprint as some people like to do - then it may be weird to press keys other than Shift and Ctrl with the mouse buttons, in which case this setting should be turned Off...
Off: The mouseclick modifiers (i.e. the Shift and Ctrl keys) can be bound totally separately from the Sneak and Sprint keys. This allows Sneak and Sprint to be reconfigured without affecting Shift and Ctrl for mouseclicks. This setting can also be used, for example, to change over to using the keyboard right hand side R Shift and R Ctrl keys for mouseclicks, which may help accessibility for people who use the mouse in their left hand.